Water demineralizing systems



July 26, 1960 J. J. eAvsowsKl Filed Dec. 18, 1957 3 Sheets-Sheet 1 //7 vI l I N Raw Wafer 25 I 27 3/ 24- 26 /9 /3 r 2/ I 7 7 7?) Drain I ifDrain 5/ 33 Cation all/lion /7 Exchange Bed. 4/ Y Deminera/ized Wafer 42Power Currenf Responsive Relay Supply 43 60 //8 0C, 1 4 7 E Timer 45ii/L.

lm/enfor Joseph .1. G'aysowsk/ July 26, 1960 J. J. GAYSOWSKI 7 2,946,733

WATER DEMINERALIZING SYSTEMS Filed Dec. 18, 1957 3 Sheets-Sheet 2 Cafion8 Anion change 884 7'0 Ora/l) Dem/hem! Wafer Marginal Power //8 I! ac,/4/

Responsive Relay [wen/0r By Joseph J 'aysowskl July 26, 1960 J. J.GAYSOWSKI 2,946,733

WATER DEMINERALIZING SYSTEMS Filed Dec. 18, 1957 5 Sheets-Sheet 3 FIG 3Exc/r. Bed.

C'L rrenf Responsive Re/ay 260 Recf/fier Inventor Joseph Gaysowsh j f ly km;

AIM.

Unite vState Patent WATER DEMINERALIZING SYSTEMS Joseph J. Gaysowski,Chicago, Ill., assignor to General Electric Company, a corporation ofNew York Filed Dec. 13, 1951, Ser. No. 703,680 22' Claims; or. 204-229 vThe present invention relates to water demineralizing systems, and moreparticularly to such systems incorporating electro-demineralizing unitsinvolving both ion exchange and electrodialysis.

It is a general object of the invention to provide in a waterdemineralizing system of the character noted, an improved automaticarrangement for controlling the anion concentration in the anolyte inthe unit and the cation concentration in the catholyte in the unit.

Another object of the invention. is to provide in anelectro-demineralizing unit, a control system of the character notedthat is arranged to supply fresh dilute anolyte to the anolyte chamberin the unit and fresh dilute catholyte to the catholyte chamber in theunit in response to undesirable high anion concentration in the anolyteand un-' desirable high cation concentration in the catholyte.

Another object of the invention is to provide in anelectro-demineralizing unit, a control system of the character noted,wherein the supply of the fresh dilute anolyte and the supply ofthe'fresh dilute catholyte are effected in response to the anode-cathodecurrent of the unit.

A further object of the invention is toprovide in anelectro-demineralizing unit, an improved arrangement for supplyinganolyte and catholyte thereto,- automatically and without stray electriccurrents exteriorly of the unit through the supply system between theanolyte and the catholyte.

A further object of the invention is to provide in anelectro-demineralizing unit, an improved anolyte and catholyte supplysystem that involves the use of porous diaphragms in the unit.

A further object of the invention is to provide in anelectro-demineralizing unit, an improved arrangement for operating theunit under substantially high water pressures.

A further object of the invention is to provide in anelectro-demineralizing unit, an improved anolyte and catholyte supplysystem that involves a pressure equalizing chamber disposed exteriorlyof the unit and arranged to insure substantially equal pressuresthroughout the unit including that of the anolyte in the anolyte chambertherof and that of the catholyte in the catholyte chamber thereof andthat of the water in the treatment chamber thereof.

A further object of the invention is to provide in anelectro-demineralizing unit, an improved anolyte and cathadditionaloperating features Patented July 28, 1960 1 'l'heinvention, both astoits organization and method ofoper ation, together with further objectsand advantages thereof, will best be understood by reference to thefollowing specification taken in connection with the acconi panyingdrawings, in which: v

Figure l is a diagrammatic illustration of a water demineralizing systemincorporating an electro-demineralizing unit and provided with anelectric control circuitembodying the present invention;

ment is thus subjected to the undesirable heating mentioned. Also, ithas been discovered that this expenditure of electric energy is wastedas respects effecting electrodialysis in the unit and causingregeneration of the anion exchange resin'and the cation exchange resinincorporat ed in the ion exchange bed of the unit. ,Also, it is notedthat'excessive catholyte concentrations result in excessive precipitatedeposits being formed in the catholyte chamber, and excessive anolyteconcentrations cause gas (such as chlorine) to be released in theanolyte chamber.

In accordance with the present invention, an automatic arrangement isprovided for efiecting the supply of fresh diluteanolyte into theanolyte chamber of the unit and the supply of fresh dilute catholyteinto the catholyte chamber of the unit in response to the undesirablehigh con centrations of anions in the anolyte and cations in thecatholyte, as reflected by the total anode-cathode current of the unit.More particularly, the specific resistance of the anolyte decreasessubstantially in response to themdesirable high concentrations of anionsin the anolyte and the specific resistance of the catholyte decreasessubstantially in response to the undesirable high concentration ofcations in the catholyte, whereby the overall resistance of the unitbetween the anode and the cathode thereof is correspondingly decreasedeffecting a corresponding increase in the anode-cathode current. In thearrangement, a marginal relay is provided in series circuit relationwith the anode and thecathode of the unit; whereby the latter relay isselectively operated and restored in accordance with the anode-cathodecurrent of the unit, and is arranged correspondingly selectively tocontrol the supply of fresh dilute anolyte to the anolyte chamber of theunit and fresh dilute catholyte to the catholyte" chamber of the unit,thereby to avoid the undesirable high anodecathode current of the unitthat is largely responsible for the undesirable heating of the waterundergoing treatment in the unit.

Referring now to Fig. 1 of the drawings, the dem-ineralizing systemthere illustrated, and embodying the features of 'the present invention,is' especially designed for home use, and essentially comprises a rawwater supply pipe 11, a deminer-alized or treated water supply pipe 12;and an telectro-demineralizing unit 13. The raw water, in the raw watersupply pipe 11 is under gauge pressure and is connected to the citywater main, not shown; while the deminer'alized .or treated watersupplypipe 1-2 is connected to thepotablewater plumbing, not shown, inthe home. The rawtwater in the supplypipe 1 1 contains substantialdissolved mineral salts supplying thereto such'cations as: Ca++, M=g++,Fe++, Na- AI+++,

etc. Moreover, this raw water may be quite hard and may have a totaldissolved solids content as high as about 70 grains/gallon (1200p.p.m.), the La Grange Park, Illinois, Well water employed in certaintests discussed hereinafter having a total dissolved solids content of64 grains/gallon (1090 ppm). In the operation of the unit 13, the rawwater is .demineralized;whereby the demineralized or treated waterdelivered to the supply pipe 12 has a total dissolved solids content notin excess of 3 grains/gallonjSlppmJ. V v H t t V -Preferably, the unit13 is of the fundamental construction and arrangement disclosed in. thecopending application of Edgar S. Stoddard, Serial No. '6 2,202,filed'J'anuary 30, 1956, now Patent i lo, 2,966,:684fahdthe unit 13essentially comprises atubula r outer shell "14, constituting a cathode,a tubular permeable diaphragm 15 arranged concentrically within thecathode 14 and cooperating to define art annular catholyte chamber 16thereb etween, a tubular permeable diaphragm 17 arranged concentricallywithin the diaphragm 15 andcooperating therewith .to define an annula rtreatment chamber 18 therebetween, and asuitableanode r19 arrangedconcentrically within the diaphragm 17 and cooperating therewith todefine an annular anolytefchamber 20 therebetween. The elements 14, 15,Hand '19 are arranged in upstanding position; and the upper and lowerends of the chambers 16, 18 and 20 are respectively closed by upperand'lower insulating headers 21 and 22. The cathode 14 may be formed ofsteel; the diaphragms 15 and 17 maybe-formed of a suitable wood orceramic material; the anode 19 may be formed of carbon, orplatinizedmetal wire, etc., and the headers 21 and 22 may be formed of asuitable synthetic organic resin. Also the treatment chamber 18 disposedintermediate the diaphragms 15 and '17 contains a porous ion exchangebed 23 of substantially annular form and substantiallycompletely-filling the same. More particularly, the bed 23 is of a mixedtype com-prising both cation exchange material and anion exchangematerial (heterogeneously mixed). Specifically, the ion exchange bed 23accommodates the ready passage therethrough of the water undergoingtreatment and essentially comprises a loosely packed mass of firstdiscrete particles of cation exchange material (preferably a syntheticorganic polymeric cation exchange resin) and of second discreteparticles of anion exchange material (preferably a synthetic organicpolymeric'anion exchange'resin), the two types of discrete particlesmentioned being soproportioned that substantially equal cation exchangeand anion exchange capacities are possessed by the bed 23, Also, it isnoted that the bed 23 is sufliciently porous that raw water undergoingtreatment suflers no substantial diminution of pressure passingtherethrough.

More particularly, this cation exchange resin is of bead-like formationand may comprise the strong-acid resin sold by Rohm and Haas under thename Amberlite IR-lZO; and this anion exchange resin is of headlikeformation and may comprise the strong-base resin sold by Rohm and Haasunder the names Amberlite IRA-400 and Amberlite IRA-410. A cationexchange resin of the type specified essentially comprises a stableinsoluble synthetic organic polymer, active acidic functional groupschemically bonded thereto and dissociable into free mobile cations toimpart a negative charge to the polymer, and water .in gel relationshipwith the polymer. Similarly, an anion exchange resin of the typespecified essentially comprises a stable insoluble synthetic organicpolymer, active basic function al-groupsrchemically bonded thereto anddissociable into free moblie anions to impart a positive charge to thepolymer, and water in gel relationship with the polymer. The activeacidic functional groups attached to the associatedorganic polymer areoriented with respect to the interfaces thereof so. as to be partiallyor-completely dissociable in the internal gel waterinto'fixed negativeions v linked to the polymer and into mobile exchangeable positive ions;and similarly, the active basic functional groups attached to theassociated organic polymer are oriented with respect to the interfacesthereof so as to be partially or completely dissociable in the internalgel water into fixed positive ions linked to the polymer and into mobileexhangeable negative ions.

Typical such polymers to which active acidic functional groups may beattached include: phenol-aldehyde resins, polystyrene-divinylbenzenecopolymers, and the like; and such suitable active acidic functionalgroups include: -SO H, COOH, and the like; SO H being usually preferredbecause of its high dissociation constant. Typical such polymers towhich active basic functional groups may be attached include:urea-formaldehyde resins, melamineformaldehyde resins,polyalkylene-polyamine-formaldehyde resins, and the like; and suchsuitable active basic functional groups include: quaternary ammoniumhydroxides, amino groups, the guanidyl group, the dicyanodiamidinegroup, and, like organic nitrogen-containing basic groups, thequaternary ammonium hydroxide groups, the guanidine and dicyanodiamidineresidue being usually preferred because of their high dissociationconstants. Normally the water in 'gel relationship with the polymershould be present in an amount of at least 15% of the weight of the dryresin.

Further, the unit 13 comprises anjupstanding conduit 24 communicatingwith the upper portion'of the catholyte chamber 1d and terminating in afunnel 25 adapted to receive fresh catholyte, and an upstanding conduit26 communicating with the upper portion of the anolyte chamber 20 andterminating in a funnel 27 adapted to receive fresh anolyte. Also, anupstanding conduit 28 communicates with the lower portion of thecatholyte chamber 15 and is provided with an upper substantiallyinverted J-shaped outlet communicating with drain plumbing, not shown;and similarly, an upstanding conduit 29 communicates with the lowerportion of the anolyte chamber 29 andis provided with an uppersubstantially inverted J-shaped outlet communicating with drainplumbing, not shown. Further, two conduits 3t} and 31 respectivelycommunicate with the lower and upper portions of the treatment chamber18 and are respectively connected to the inlet and to the outlet of apump 33; whereby operation of the pump 33 effects local circulation ofthe water in the treatment chamber 18 downwardly therethrough andthrough the porous ion exchange bed 23 and into ion exchange relationtherewith, the water proceeding from the lower portion of the treatmentchamber 18 via the conduit 38 to the pump 33; and therefrom via theconduit 31 back to the upper portion of the treatment chamber 18;whereby the circulated water is demineralized with the correspondingdegeneration of the cation exchange material and the anion exchangematerial in the bed 23.

In the unit 13, the raw water supply pipe 11 is directly connected tothe upper portion of the treatment chamber 18; and the demineralizedwater supply pipe 12 is directly connected to the lower portion of thetreatment chamber 18. Also the raw water supply pipe 11 is connected totwo conduits 34 and 35 that are disposed above and in cooperatingrelation with the two funnels 25 and 27; which conduits 34 and 35 arerespectively provided with solenoid controlled valves 36 and 37. Thevalve 36 isnormally biased into its closed position and when thesolenoid thereof is energized, it is operated into its open position inorder to supply raw water as fresh dilute catholyte via the conduit 34,the funnel Z5 and the conduit 24 into the 'catholyte chamber 16, so thatcatholyte therein is displaced via the conduit 28 to the drain plumbing,with the result that the concentration of the cations in the catholytein the catholyte chamber16 is reduced. Similarly, the valve 37 isnormally biased into its closed position and when the solenoid thereofis energized, it is operated intoits'open positio'n'in order to supplyrawwater as fresh dilute anolyte via the conduit-35, the funnel Z7,

and the conduit 26 into the anolyte chamber 20, sothat the anolytetherein is displaced via the conduit 29 to the drain, with the resultthat the concentration of the anions in the anolyte in the anolytechamber 20 is reduced.-

In passing, it is noted that it is not essential that individual valves36 and 37 be arranged in the respective conduits 34 and 35, as a commonvalve arranged in the common connection to the raw water supply pipe 11will serve the function noted, nevertheless, the arrangement disclosedis very convenient in that it absolutely insures the proper division ofthe anolyte and the catholyte into the funnels 27 and 25, as describedabove.

A valve- 38 is arranged in the demineralized water supply pipe 12; andwhen the valve 38 is opened, the demineralized water flows from thedemineralized water supply pipe 12 and raw water flows from the rawwater supply pipe 11 into the upper portion of the treatment chamber 23and thence downwardly through the ion exchange bed 23 and ultimatelyinto thedemineralized water supply pipe 12, with the result that the rawwater is demineralized, as previously explained.-

Further, the system 100 comprises a source of electric power supply thatmay be of 118 volts, A.-C., singlephase and including two conductors 41and 42, the conductor 41 being connected to ground potential. Arectifier 43 is provided and comprises a pair of input terminalsrespectively connected to the conductors 41 and 42 and a pair of outputterminals respectively connected .to the grounded conductor 41 and to anungrounded conductor 44, the conductor 44 being connected to thepositive output terminal of the rectifier 43 and the grounded conductor41 being connected to the negative output terminal of the rectifier 43.Also, a timer 45 is provided that includes an electric timer motor 46 ofthe synchronous type, and preferably a Telechron timer motor; whichtimer motor 46 selectively controls a pair of. switches 47 and 48. Theswitch 47 respectively terminates the conduc: tor 44 and a conductor 49;while the switch 48 respectively terminates the conductor 44 .and aconductor 50.

The pump 33 is driven by an electric drive motor 51, one

terminal of which is connected to the grounded conductor 41 and theother. terminal of which is connected to the conductor 50. The solenoidsof the valves 36 and 37 are connected in parallel relation across thegrounded conductor 41 and the conductor 49. Further, the system 100comprises a current responsiverelay 60 that is provided with a windingincluded in a series connection between the conductor 44 and a conductor61 connected to the anode 19. Also, the relay 60 is provided with acontact bridging member 62 operatively associated with a pair ofcontacts respectively terminating the conductors 44 and 49. Finall thecathode 14 is connected to the grounded conductor 41.

In the operation of the unit 13, a direct current is supplied from theconductor 44 via the winding of the relay 60 and the conductor 61 to theanode 19; which current is further conducted through the anolyte in theanolyte chamber 20, the diaphragm 17, the water undergoing treatment inthe treatment chamber 18, as wellas the ion exchange bed 23 in thetreatment chamber 18, the diaphragm 15 and the catholyte in thecatholyte chamber 16 to the cathode 14 and thence to the groundedconductor 41, completing the circuit across the output terminals of therectifier 43. The magnitude of the anode-cathode current that flows inthe above-traced circuit is dependent upon the total resistance of theunit 13 between the anode 19 and the cathode 14; and at this point, itmay be assumed that the current mentioned is modest so that the relay 60remains in its restored position, the relay-60 being of the marginaltype. 7

As time proceeds, the resin bed 23 is regenerated, with the result thatthe sorbed cations of the mineral salts are exchanged forhydrogen ionswith the migration ofthe cations of the mineral salts through thediaphragm 15 into the catholyte in the catholyte chamber 16 so. that Hthe cation concentration in the catholyte is increased, and

with the resultthat the .sorbed anions of the mineral salts areexchanged for hydroxyl ions with the migration of the anions of themineral salts through the diaphragm '17 into the anolyte in the anolytechamber 20 so that the anion concentration in the anolyte is increased.As the cation concentration in the catholyte is increased, the specificresistance of this portion of the path between the anode 19 and thecathode 14 is reduced; and likewise, as the anion concentration in theanolyte is increased, the specific resistance of this portion of thepath between the anode 19 and the cathode 14 is reduced; whereby theoverall resistance of the unit 13 between the anode 19 and the cathode14 is progressively reduced, with the result that the anode-cathodecurrent is progressively increased.

Ultimately, when the anode-cathode current reaches a predeterminedvalue, the winding of the relay 30 is sufficiently energized that thelatter relay operates, whereby the contact bridging member 62 connectsthe conductor 44 to the conductor 49, with the result that the solenoidsof the valves 36 and 37 are energized in parallel relation causing thevalves 36 and 37 to be operated into their open positions. Thus freshcatholyte is supplied into the catholyte chamber 16 with the resultingdilution of the cation concentration therein, and fresh anolyte issupplied into the anolyte chamber 20 with the resulting dilution of theanion concentration therein; whereby the specific resistance of thecatholyte and the specific resistance'of the anolyte are both increased,with a corresponding reduction in the anode-cathode current. Ultimately,the resistance of the unit 13 between the anode 19 and the cathode 14 isincreased sutficiently that the anodecathode current is reducedsufficiently that the relay 6i restores, so that the contact bridgingmember 62 opens the previously tracedci'rcuit for energizing in parallelthe solenoids of the valves 36 and 37. Accordingly,.the valves 36 and 37are reclosed cutting off the supply of fresh catholyte intothe catholytechamber 16 and the supply of fresh anolyte into the anolyte chamber 20.

Also in the operation of the system, the timer 45 periodically closesand thenreopens the switch 47 thereby periodically completing analternative connection between the conductors 44 and 49 with the resultthat the valves 36 and 37 are opened during the completion of theconnection in the manner previously explained.

At this point, 'it is noted that the provision of the switch 47 in thetimer 45 is altogether alternative with respect to the provision of thecurrent responsive relay 60; whereby the switch 47 in the timer 46 maybe omitted, if desired; However, the arrangement of the switch 47 in thetimer 45 in the control system is advantageous as it in effectanticipates the expected future operation of the relay 60, therebyminimizing the number of operations of the relay 60 during a protractedtime interval.

Also during the operation of the system, the timer 45 intermittentlycloses and reopens the set of switch springs 48, thereby effectingcorresponding intermittent operation of the electric drive motor 51,whereby the pump 33 is correspondingly intermittently operated; Moreparticularly, the pump 33 is operated so that the water in the treatmentchamber 18 is circulated therethrough at a relatively low overall rate,the water in the treatment chamber being changed about once per hour.

In a constructional example of the water d'emineralizing unit 13, theexternal diameter of the diaphragm 17 was 4"; the internal diameter ofthe diaphragm 15 was about 12''; the internal diameter of the cathode 14was about 16"; the height of the treatment chamber 18' between theheaders 21 and 22 Was about 36"; and the thickness of the treatmentchamber 18 between the diaphragms 17 and 15 was about 4". The volume 'ofthe treatment chamber 18 was about 2.1 cu. ft.; the water pressure inthe treatment chamber was not in excess of 45. p.s.i.;. and

the power consumptionat 60 to volts D.- C. wasin bed 23 was arrangedsubstantially completely to fill the treatment chamber 18; whereby ithad a volume of about 2.1 cu. ft. and was composed of substantiallyequal volurnes of the cation exchange resin Amberlite IR- 120 and of theanion exchange resin Amberlite IRA-410; the pump 33was arranged tocirculate water at a rate in the general range 1 to 6 gallons/hour; andthe water employed in the test was La Grange Park, Illinois, well water.In the operation of the unit 13, this raw water having a total dissolvedsolids content of 64 grains/ gallon was demineralized to produce treatedwater having a total dissolved solids content not in excess of 3 grains/gallon.

In a test of this embodiment of the system 1%, and with the switch 47blocked in its open position, a drawoir' of 10 gallons of demineralizedwater was made from the demineralized water supply pipe 12, with thecorresponding supply of 10 gallons of the La Grange Park, Illinois, wellwaterfront the raw water supply pipe 11 into the treatment chamber 18.During the draw-oft, the relay 6t) operated automatically; and at thetime of operation of the relay 60, it was observed: the anodecathodecurrent was 8.1 amperes D.-C.; the pH of the anolyte was 1.7 and had atemperature of 60 C.; the pH of the catholyte was 12.5 and had atemperature of 42 C.; and the temperature of the treated water in thedraw-oil was 44 C. When the relay 69 operated, the La Grange Park,Illinois, well water was supplied from the raw water supply pipe 11 insubstantially equal amounts as catholyte into the catholyte chamber 16and as anolyte into the anolyte chamber 20, with the result that therelay 611 restored after about 18 minutes. 01 course, the draw-off tookplace in a time interval of about 2 minutes, and during the timeinterval of 18 minutes 4% gallons of the La Grange Park, Illinois,

' well water was supplied substantially equally to the chambers 16 and20. At this time, and upon restoration of the relayfit), it was observedthat the anodecathode current had declined to 4.3 amperes D.-C.; the pHof the anolyte was increased to 2.3 and the temperature thereof wasreduced to 40 C.; the pH of the catholyte was reduced to 12.4 and thetemperature thereof was reduced to 40 C. The combined anolyte displaced-from the anolyte chamber 20 and the catholyte displaced from thecatholyte chamber 16 was caught and was found to have a volume of 4%gallons; and the pH of the mixture of the anolyte and the catholyte was12.0.

Operation of the system 161) was continued, and about 2 /2 hours later,the anode-cathode current had declined to 2.9 amperes D.-C.; and another10 gallon draw-bit was made :from the demineralized water supply pipe 12with the result that the anode-cathode current increased to 4.3 amperesat the conclusion of this draw-oil. This magnitude of the anode-cathodecurrent was not effective to bring about operation of the relay 60 as itwas of the marginal type, as previously noted.

In a protracted and continuous run of the system 1111) without thedraw-01f of any dernineralized water therefrom and involving a timeinterval of about 12 days, it was established that the anode-cathodecurrent did not become excessive by virtue of the automatic intermittentoperation of the relay 60 as previously explained. During thisprotracted run, the daily energy consumption of the unit 13 averaged 2.7kw] hr. at 30 volts D-C. applied between the anode 19 and the cathode14.

By way of contrast, it is pointed out that in the absence of the currentresponsive relay 6% and without control of the supply of fresh anolyteand fresh catholyte to the unit 13, it is not'feasible to permitunattended operation of the unit 13, since the anode-cathode current canprogressively increase and ultimately reach a value substantially inexcess of -12 amperes D.-C. in about 24 hoursof operation of the unit 13with damage to the rectifier 43.

'Referring now to Fig. 2 01 the drawings, the demineralizing system 2011there illustrated is fundamentally of the same construction as thesystem shown in Fig. 1; whereby corresponding reference characters havebeen employed therein to identify corresponding elements. Accordingly,the unit 113 comprises the anode 119, the cathode 114, the twodiaphragms 115 and 117 and the mixed resinnbed 123, as well as the threechambers 116, 118 and 121), as previously described. In this arrangementor the unit 113, the catholyte in the catholyte chamber 116 and theanolyte in the anolyte chamber are under pressure, and substantially atthe same pressure as the Water in the treatment chamber 118; whichresult is achieved by forming the diaphra grns 115 and 117 of suitableceramic or wood material that is not only permeable but alsosufliciently porous that the water undergoing treatment in the treatmentchamber 118 can penetrate the diaphragms 115 and 117 and thus supplycatholyte into the corresponding catholyte chamber 116 and anolyte intothe corresponding anolyte chamber 120.

More particularly, in this arrangement of the unit 113, a solenoidcontrolled valve 136 (corresponding in general function to the valve 36of the system 100) is arranged in the conduit 128 communicating with thelower portion of the catholyte chamber 116; and similarly, a solenoidcontrolled valve (corresponding in general function to the valve 35 ofthe system 1110) is arranged in the conduit 129 communicating with thelower portion of the anolyte chamber 121 Also a float valve is arrangedin the conduit v124 communicating with the upper portion of thecatholyte chamber 116, and afloat valve is arranged in the conduit 126communicating with the upper portion of the anolyte chamber 120. Thefloat valve 1811 includes a casing containing a float proper 181 that isadapted to float upon catholyte in the associated casing so as normallyto close an associated valve seat communicating via a conduit 182 thatcommunicates with a casing 183 containing catalytic material 184, thecasing 183 further communicating with the atmosphere. The float valve185 includes a casing containing a float proper 186 that is adapted tofloat upon anolyte in the associated casing so as normally to close anassociated valve seat communicating via a conduit 187 with theatmosphere.

In the operation of the unit 113, when the valves 135 and 136 areopened, anolyte and catholyte proceed from the respective anolytechamber 1211 and catholyte chamber '116 to drain, with the resultingreduction in pressure in the two chambers 12% and 116. When the pressureof the anolyte in the anolyte chamber 126 is thus reduced, treated waterin the treatment chamber 118 proceeds through the associated porousdiaphragm 117 into the anolyte chamber 120, thereby diluting theconcentration of anions in the anolyte and again filling the anolytechamber 121) so as to restore the pressure of the anolyte therein.Similarly, when the pressure of the catholyte in the catholyte chamber116 is thus reduced, treated water in the treatment chamber 118 proceedsthrough the associated porous diaphragm 115 into the catholyte chamber1116, thereby diluting the concentration of cations in the catholyte andagain filling the catholyte chamber 116 so as to restore the pressure ofthe catholyte therein.

Of course, when anolyte is withdrawn from the anolyte chamber 120, asdescribed above, the anolyte level therein falls so .that the float 186opens its associated valve seat with the result that the anolyte chamber121) is placed in communication with the atmosphere. On the other hand,when the supply of anolyte into the anolyte chamber 120 is restored, itrises through the conduit 126 into. the casing of the float valve 185returning the float 186 into closed position with its associated valveseat so as to cutofi .the communication between the casing of the floatvalve 185 and the atmosphere. It will also be understood that thisarrangement permits the escape of oxygen and other gaseous products thatmay accumulatein the anolyte in, the operation ofthe unit 113, sincesuch gaseous products will rise into the casing of the float valve 185causing the float proper 186 to move into its open position with itsassociated valve seat with the resulting venting ofthe gaseous productsintolthe atmosphere. This venting of the gas from the anolyte chamber120 reduces the pressure therein so as-to prevent the backflow ofanolyte therefrom through the diaphragm 117 into the treatment chamber118 and into contact with the resin bed 123. Thus, make-up liquid isrequired to fill the anolyte chamber 120 completely, as a result of theaction of the float valve 185.

I Of course, when catholyte is withdrawn from the catholyte chamber 116,as described above, the catholyte level therein falls so that the float181 opens its associated valve seat with the result that the catholytechamber 116 is placed in communication with the atmosphere. On the otherhand, when the supply of catholyte into the catholyte chamber 116 isrestored, it rises through the conduit 124 into the casing of the floatvalve 180 returning the float 181 into its closed position with itsassociated valveseat so as to cut-ofi the communication between thecasing of the float valve 180 and the atmosphere. It will also beunderstood that this arrangement permits the escape of hydrogen that mayaccumulate in the catholyte in the operation of the unit 113, since suchgaseous'product will rise into the casing of the float valve 180 causingthe float proper 181 to move into its open position with its associatedvalve seat with the resulting venting of the gaseous hydrogen into thecasing 183. This venting of the gas from the catholyte chamber 116reduces the pressure therein so as to prevent the backflow of catholytetherefrom through the diaphragm 115 into the treatment chamber 118 andinto contact with the resin bed 123. .Thus, make-up liquid is requiredto fill the catholyte chamber 116 completely,as a result of the actionof the float valve 180.

As previously noted, the casing 183 contains the charge of catalyst 184that may essentially comprise platinum beads so as to bring about awater-producing reaction between the hydrogen escaping from the casingof the float valve 180 and atmospheric oxygen. Thewater thusproduceddrains from the casing 183 back into the conduit 182 so that it mayultimately be drained back into the casing of the float valve 180incident'to the next operation thereof into its open position; wherebythe water thus produced is returned to the catholyte chamber 116.

The fundamental mode of operation of the unit 113 is the same as thatpreviously described in conjunction with the unit 13, whereby it will beunderstood that the relay 160 operates and restores in response torespective high and low concentrations of the anions in the anolyte andof the cations in the catholyte correspondingly controlling thesolenoids of the valves 135 and 136 so as to govern the supply of freshanolyte into the anolyte chamber 120 and the supply of fresh catholyteinto the catholyte chamber 116; all in the manner previously describedfor the purpose explained in conjunction with the system 100. v

Referring now to Fig. 3 of the drawings, the demineralizing system 300there illustrated is fundamentally the same construction as the system100 shown in Fig. 1, but incorporate certain features of the system 200of Fig., 2; whereby corresponding reference characters have beenemployed therein to identify corresponding elements. Accordingly, theunit 213 comprises the anode 219, the cathode 214, the two diaphragms215 and 217 and the mixed resin bed 223, as well as the three chambers216, 218 and 220, as previously described. In this arrangement of theunit 213, the catholyte in the catholyte chamber 216 and the anolyte inthe anolyte chamber 220 are under pressure, and substantially at thesamepressure as the water in the treatment chamber 218; which result isachieved by the ultilization of a catholyte-anolyte supply tank 293formed of insulating material and mutually connected to the raw watersupply pipe 211 and to the catholyte chamber 216 and to the anolytechamber 220.

More particularly, an upstanding conduit 291 projects through the bottomheader 222 and communicates with the upper portion of the catholytechamber 216; and similarly, a conduit 292 projects through the bottomheader 222 and communicates with the upper portion of the anolytechamber 220. The supply tank 293 may be formed of a suitable moldedorganic resin and comprises structure defining therein a centralcompartment 294, two laterally disposed adjacent end compartments 295and 296 and a communicating common overhead space 297. The centralcompartment 294 is connected directly to the raw Water supply pipe 211,while the end compartments 295 and 296 are respectively connected to theouter extremities of the conduits 291 and 292; and finally a body orcharge of pressure-transmitting electrical-insulating liquid 297 isarranged in the common space 297 in contact with the liquidsrespectively arranged in the compartments 294, 295 and 296. Moreparticularly, the body of insulating liquid 297' may essentiallycomprise a light mineral oil; and specifically, the body or charge 297'comprises an insulating liquid that is incompressible and that has aspecific gravity that is lower than that of water and that is immisciblewith water and that serves to insulate from each other the bodies orpools of water in the respective compartments 294, 295 and 296. Finally,the overhead space 297 in the supply tank 293 is connected by a conduit298 with the atmosphere; which conduit 298 includes a normally closedvalve 299.

In this arrangement of the unit 213, the diaphragms 215 and 217 areformed of suitable material such as wood veneer or thin ceramic, that ispermeable, but not porous; which diaphragms 215 and 217 are entirelycommensurate in construction with the diaphragms 15 and 17 of the unit13, as distinguished from the diaphragms and 117 of the unit 113 thatare also porous. Furthermore, in the unit 213, the conduits 228 and 229respectively communicating with the lower portions of the chambers 216and 200 respectively include the solenoid controlled valves 236 and 235;while the conduits 224 and 226 respectively communicating with the upperportions of the chamber 216 and 200 respectively include the floatvalves 28!) and 285.

Considering now the general mode of operation of the system390, it willbe under-stood that raw water under pressure is supplied from the rawwater supply pipe 211 into the treatment chamber 218 in the unit 213,and also into the compartment 294 in the tank 293. The raw watersupplied to the treatment chamber 218 proceeds downwardly through theion exchange bed 223, wherein it is demineralized, in the mannerpreviously explained, and is ultimately supplied into the demineralizedwater supply pipe 212. Also the raw Water under pressure in the centralcompartment 294 of the tank 293 exerts pressure upon the insulatingliquid 297'; whereby the insulating liquid 297 exerts pressure upon thebody of catholyte'contained in the compartment 295 and upon the body ofanolyte contained in the compartment 296. Accordingly, the pressure isexerted between the catholyte in the compartment 295 of the tank 293 andthe body of catholyte contained in the catholyte chamber 216 of the unit213, via the conduit 291; and likewise the pressure is exerted betweenthe anolyte in the compartment 296 of the tank 293 and the bodyof'anolyte contained in the anolyte chamber 220 of the unit 213, via theconduit 292. When the valve 235 is opened, anolyte from the anolytechamber 220 is conducted to the exterior so that anolyte from thecompartment 296 in the tank 293 proceeds through the conduit 292 intothe anolyte chamher 220 with. the result that the anolyte in the'anolytechamber 229 is diluted with respect to the anions therein for thepurpose previously explained. Similarly, when the valve 236 is opened,catholyte from the catholyte chamber 216 is conducted to the exterior sothat catholyte from the compartment 295 in the tank 233 proceeds throughthe conduit 291 into the catholyte chamber 216 with the result that thecatholyte in the catholyte chamber 216 is diluted with respect to thecations therein for the purpose previously explained. When anolyte is.conducted from the compartment 296 in the tank 293, the pressuretherein is momentarily reduced causing lie water in the centralcompartment 294 to overflow the associated structure and spill into thecompartment 296 by virtue of the pressure in the raw water supply pipe211; which raw water thus supplied to the compartment 294 from the rawwater supply pipe 211 proceeds through the body of insulating liquid2,97, thereby maintaining the pool of raw water in the compartment 294in insulating relation with respect to the pool of anolyte in thecompartment 2%, while supplying the raw water from the compartment 294as anolyte into the compartment 296. When anolyte is conducted from thecompartment 295 in the tank 293, the pressure therein is momentarilyreduced causing the Water in the central compartment 2% to overflow theassociated structure and spill into the compartment 295 by virtue of thepressure in the raw water supply pipe 211; which raw Water supplied tothe compartment 294 from the raw Water supply pipe 211 proceeds throughthe body of insulating liquid 297, thereby maintaining the pool of rawwater in the compartment 294 in insulating relation with respect to thepool of catholyte in the compartment 295, while supplying the raw waterfrom the compartment 294 as catholyte into the compartment 295.

Hence, the tank 293 serves the function of supplying anolyte to theanolyte chamber 220 and catholyte to the catholyte chamber 216 from theraw water supply pipe 211, without electrical conduction between theanolyte and the catholyte in the tank 293, and while maintaining thepressure of the anolyte and the catholyte substantially at the pressureof the raw water in the raw Water supply pipe 211 and consequently atthe pressure of the water undergoing treatment in the chamber 218;whereby there is no substantial pressure differential across either ofthe diaphragms 215 or 217 in the operation of the system 300.

Also it will be appreciated that the arrangement of the valve 299 in theconduit 298 accommodates initial charging of the insulating liquid 297'into the overhead space 297 in the tank 293, as well as the removal ofair or other gases from time to time, as they may accumulate in theupper portion of the tank 293.

The fundamental mode of operation of the unit 213 is the same as thatpreviously described in conjunction with the unit 13; whereby it will beunderstood that the relay 260 operates and restores in response torespective high and low concentration of the anions in the anolyte andof the cations in the catholyte correspondingly controlling thesolenoids of the valves 235 and 236 so as to govern the supply of 'freshanolyte intorthe anolyte chamber 220 and the supply of fresh catholyteinto the catholyte chamber 216; all in the manner previously describedfor the purpose explained in conjunction with the system 106.

In view of the foregoing, it is apparent that there has been provided awater demineralizing system, incorporating an electro-demineralizingunit involving both ion exchange and electrodialysis, and comprising anautomatic control. arrangement for supplying fresh anolyte and freshcatholyte to the unit as required, so as to maintain the anode-cathodecurrent of the unit within the proper operating current range thereof.

While there has been described what is at present considered .to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended I2 claims all such modifications as fall within the truespirit and scope of the invention.

What is claimed is:

1. In a water demineralizing system: a demineralizing unit includingstructure defining a treatment chamber and an anolyte chamber and acatholyte chamber with a first diaphragm as a common wall between saidtreatment chamber and said anolyte chamber and with a second diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber, and a porous ion exchange bed arranged in said treatmentchamber and characterized by both cation exchange and anion exchange; aninlet pipe adapted to contain raw water under pressure and connected tosaid treatment chamber; an outlet pipe adapted to contain demineralizedwater under pressure and connected to said treatment chamber; valvemechanism for controlling the flow of water from said inlet pipe throughsaid treatment chamber and into contact with said ion exchange bcd andthence through said outlet pipe with the result that the raw waterpassing through said treatment chamber is demineralized and said ionexchange bed is correspondingly degenerated; first conduit means forsupplying fresh anolyte into said anolyte chamber; second conduit meansfor supplying fresh catholyte into said catholyte chamber; a powercircuit for conducting a direct current from said anode to said cathode,whereby said ion exchange bed is regenerated with the migration of thesorbed anions and cations of the mineral salts respectively into saidanolyte and into said catholyte with the result that the ionconcentrations therein are increased; valve apparatus for controllingthe supply of fresh anolyte from said first conduit means into saidanolyte chamber and the supply of fresh catholyte from said secondconduit means into said catholyte chamber; and automatic means governedby the ion concentrations in said anolyte and in said catholyte forselectively controlling said valve apparatus, so that said valveapparatus is opened in response to relatively high concentrations ofions in said anolyte and in said catholyte and is closed in response torelatively low concentrations of ions in said anolyte and in saidcatholyte.

2. The system set forth in claim 1, wherein said bed comprises syntheticorganic polymeric cation exchange resin and synthetic organic polymericanion exchange resm.

3. In a water demineralizing system: a demineralizing unit includingstructure defining a treatment chamber and an anolyte chamber and acatholyte chamber with a first diaphragm as a common Wall between saidtreat-ment chamber and said anolyte chamber and with a second diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber, and a porous ion exchange bed arranged in said treatmentchamber and characterized by both cation exchange and anion exchange; aninlet pipe adapted to contain raw water under pressure and connected tosaid treatment chamber; an outlet pipe adapted to contain demineralizedwater under pressure and connected to said treatment chamber; valvemechanism for controlling the flow of water from said inlet pipe throughsaid treatment chamber and into contact with said ion exchange bed andthence from said outlet pipe with the result that the raw water passingthrough said treatment chamber is demineralized and said ion exchangebed is correspondingly degenerated; first conduit means for supplyingfresh anolyte into said anolyte chamber; second conduit means forsupplying fresh catholyte into said catholyte chamber; a power circuitfor conducting, a direct current from said anode to said cathode,whereby said ion exchange bed is; regenerated withflthe migration of thesorbed anions and cations .of the minerai salts respectively into saidanolyte and into said oath:-

olyte with the result that the specific resistance f; said power circuitbetween said' anode and said cathode is reduced; valve apparatus forcontrolling the supply of fresh anolyte from said first conduit meansinto said anolyte chamber and the supply of fresh catholyte from saidsecond conduit means into said catholyte chamber; and automatic meansgoverned by the specific resistance of said power circuit between saidanode and said cathode for selectively controlling said valve apparatus,so that said valve apparatus is opened in response to a relatively lowspecific resistance of said power circuit and is closed in response to arelatively high specific resistance of said power circuit.

4. In a water demineralizing system: a demineralizing unit includingstructure defining a treatment chamber and an anolyte chamber and acatholyte chamber with a first diaphragm as a common wall between saidtreatment chamber and said anolyte chamber and with a second diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber and a porous ion exchange bed arranged in said treatment chamberand characterized by both cation exchange and anion exchange; an inletpipe adapted to contain raw water under pressure and connected to saidtreatment chamber; an outlet pipe adapted to contain demineralized waterunder pressure and connected to said treatment chamber; valve mechanismfor controlling the flow of Water from said inlet pipe through saidtreatment chamber and into contact with said ion exchange bed and thencefrom said outlet pipe with the result that the raw water passing throughsaid treatrhent chamber is demineralized and said ion exchange bed iscorrespondingly degenerated; first conduit means for supplying freshanolyte into said anolyte chamber; second conduit means for supplyingfresh catholyte into said catholyte chamber; means for conducting adirect current from said anode to said cathode, whereby said ionexchange bed is regenerated with the migration of the sorbed anions andcations of the mineral salts respectively into said anolyte and intosaid catholyte; valve apparatus for controlling the supply of freshanolyte from said first conduit means into said anolyte chamber and thesupply of fresh catholyte from said second conduit means into saidcatholyte chamber; and automatic means governed by said anode-cathodecurrent for selectively controlling said valve apparatus, so that saidvalve apparatus is opened in response to a relatively largeanode-cathode current and is closed in response to a relatively smallanode-cathode current. a

5. The system set forth in claim 4, wherein said automatic meansessentially comprises a relay provided with a Winding arranged in seriescircuit relation with said anode and said cathode.

6. In a water demineralizing system: a demineralizing unit includingstructure defining a treatment chamber and an anolyte chamber and acatholyte chamber,

with a first diaphragm as a common wall between said treatment chamberand said anolyte chamber and with a second diaphragm as a common wallbetween said treatment chamber and said catholyte chamber, an anode insaid anolyte chamber, a cathode in said catholyte chamber and a porousion exchange bed arranged in said treatment chamber and characterized byboth cation exchange and anion exchange; an inlet pipe adapted tocontain raw water under pressure and connected to said treatmentchamber; an outlet pipe adapted to contain demineralized water underpressure and connected to said treatment chamber; valve mechanism forcontrolling the fiow of water from said inlet pipe through saidtreatment chamber and into contact with said ion exchange bed and thencefrom said outlet pipe with the.

result that the raw water passing through said treatment chamberisdemineralized and said ion exchange bed is correspondinglydegenerated; first conduit means for supplying fresh anolyte into saidanolyte chamber; second conduit means for supplying fresh catholytevinto said catholyte chamber; valve apparatus for controlling the flow offresh anolyte from said first conduit through said anolyte chamber tothe exterior and the flow of fresh catholyte from said second conduitthrough said catholyte chamber to the exterior; a power circuit forconducting a direct current from said anode to said cathode, wherebysaid ion exchange bed is regenerated with the migration of the sorbedanions and cations of the mineral salts respectively into said anolyteand into said catholyte with the result that the ion concentrationstherein are increased; and automatic means governed by the ionconcentrations in said anolyte and in said catholyte for selectivelycontrolling said valve apparatus, so

that said valve apparatus is opened in response to relatively highconcentrations of ions in said anolyte and a second diaphragm as acommon wall between said treatment chamber and said catholyte chamber,an anode in said anolyte chamber,ta cathode in said catholyte chamberand a porous ion exchange bed arranged in said treatment chamber andcharacterized by both cation exchange and anion exchange; an inlet pipeadapted to contain raw Water under pressure and connected totsaidtreatment chamber; an outlet pipe adapted to contain demineralized waterunder pressure and connected to said treatment chamber; valve mechanismfor controlling the flow of demineralized water from said outlet pipe,whereby raw water is supplied from said inlet pipe into said treatmentchamber and into contact with said ion exchange bed with the result thatthe raw water is demineralized and said ion exchange bed iscorrespondingly degenerated; first conduit means for supplying freshanolyte into said anolyte chamber; second conduit means for supplyingfresh catholyte into said catholyte chamber; a first valve forcontrolling the flow of fresh anolyte from said first conduit throughsaid anolyte chamber to the exterior; a second valve for controlling thefresh catholyte from said second conduit through said catholyte chamberto the exterior; a power circuit for conducting a direct current fromsaid anode to said cathode, whereby said ion exchange bed is regeneratedwith the migration of the sorbed 'anions and cations of the mineralsalts respectively into said anolyte and into said catholyte with theresult that the ion concentrations therein are increased; and automaticmeans governed by the ion concentrations in said anolyte and in saidcatholyte for selectively controlling said valves, so thatsaid valvesare opened in response to relatively high concentrations of ions in saidanolyte and in said catholyte and are closed in response to relativelylow concentrations of ions in said anolyte and in said catholyte. i t

9. The system set forth in claim 8, wherein said first valve is arrangedbetween said first conduit and the inlet of said anolyte chamber andsaid second valve-is arranged between said second conduit and the inletof said catholyte chamber.

10. The system set forth in claim 8, wherein said first valve isarranged between the outlet of said anolyte chamber and the exterior,and said second valve is i r arranged between the outlet of saidcatholyte chamber and the exterior.

11. In a water dernineralizing system: a demineralizing unit includingstructure defining a treatment chamber and an anolyte chamber and acatholyte chamber with a first diaphragm as a common wall between saidtreatment chamber and said anolyte chamber and with a second diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, and a cathode in saidcatholyte chamber; an inlet pipe adapted to contain raw water underpressure and connected to said treatment chamber; an outlet pipe adaptedto contain demineralized Water under pressure and connected to saidtreatment chamber; valve mechanism for controlling the fiow of waterfrom said inlet pipe through said treatment chamber and thence from saidoutlet pipe; valve apparatus for controlling the flow of raw water fromsaid inlet pipe into said anolyte chamber and into said catholytechamber and the flow of anolyte from said anolyte chamber to theexterior and the flow of catholyte from said catholyte chamber to theexterior; a source of DC. power; means connecting said source betweensaid anode and said cathode; whereby a D.-C. current flows from saidanode to said cathode with the result that the water in said treatmentchamber is demineralized with migrations of the anions and the cationsof the mineral salts respectively into said anolyte and into saidcatholyte, so that the ion concentrations therein are increasedefiecting a corresponding increase in the anode-cathode current; andrelay means governed by the amplitude of the anode-cathode current forselectively controlling said valve apparatus, so that said valveapparatus is opened in response to a relatively large 1 anode-cathodecurrent and is closed in response to a relatively small anode-cathodecurrent.

12. The system set forth in claim 11, wherein said relay means includesa winding arranged in series circuit relation with said anode and saidcathode, said relay operating in response to a given anode-cathodecurrent to efiect opening of said valve apparatus and restoring inresponse to less than said given anode-cathode current to effect closingof said valve apparatus.

13. In an electrolytic system, a unit including first structure defininga treatment chamber and an anolyte chamber and a catholyte chamber witha first permeable diaphragm as a common wall between said treatmentchamber and said anolyte chamber and with a second permeable diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber, means for supplying a first aqueous solution containing anelectrolyte into said treatment chamber, closed insulating secondstructure defining therein three separated compartments and a connectingoverhead space common to said three compartments, a supply pipe adaptedto contain a second aqueous solution under pressure and containing anelectrolyte, a first conduit connecting said supply pipe to a first ofsaid compartments, a second conduit connecting a second of saidcompartments to said anolyte chamber, a third conduit connecting a thirdof said compartments to said catholyte chamber, means for applying adirect voltage between said anode and said cathode, whereby said firstaqueous solution is subjected to electrodialysis with the migration ofthe anions and the cations therein respectively into the anolytecontained in said anolyte chamber and into the catholyte contained insaid catholyte chamber, means for selectively controlling the dischargeof anolyte from said anolyte chamber to the exterior and the dischargeof catholyte from said catholyte chamber to the exterior, and a chargeof insulating liquid arranged in said overhead space and in contact withthree bodies of said second solution respectively contained in saidthree compartments, said charge of insulating liquid beingincompressible and having a specific gravity lower than that of saidsecond solution and being immiscible therewith and serving to insulatefrom each other the three bodies of said second solution respectivelycontained in said three compartments andiserving to transmit thepressure of the body of said second solution contained in said firstcompartment to the other two bodies of said second solution respectivelycontained in said second and third compartments, whereby the dischargeof anolyte from said anolyte chamber effects the flow of said secondsolution from said first compartment through said charge of liquid intosaid second compartment and thence into said anolyte chamber and thedischarge of catholyte from said catholyte chamber effects the flow ofsaid second solution from said first compartment through said charge ofliquid into said third compartment and thence into said catholytechamber.

14-. In an electrolytic system, a unit including first structuredefining a treatment chamber and an anolyte chamber and a catholytechamber with a first permeable diaphragm as a common wall between saidtreatment chamber and said anolyte chamber and with a second permeablediaphragm as a common wall between said treatment chamber and saidcatholyte chamber, an anode in said anolyte chamber, a cathode in saidcatholyte chamber, means for supplying a first aqueous solutioncontaining an electrolyte into said treatment chamber, closed insulatingsecond structure defining therein three separated compartments and aconnecting overhead space common to said three compartments, a supplypipe adapted to contain a second aqueous solution under pressure andcontaining an electrolyte, a first conduit connecting said sup-ply pipeto a first of said compartments, a second conduit connecting a second ofsaid compartments to said anolyte chamber, a third conduit connecting athird of said compartments to said catholyte chamber, means for applyinga direct voltage between said anode and said cathode, whereby said firstaqueous solution is subjected to electrodialysis with the migration ofthe anions and the cations therein respectively into the anolytecontained in said anolyte chamber and into the catholyte contained insaid catholyte chamber, so that the ion concentrations therein areincreased, valve apparatus for controlling the discharge of anolyte fromsaid anolyte chamber to the exterior and discharge of catholyte fromsaid catholyte chamber to the exterior, automatic means governed by theion concentrations in said anolyte and in said catholyte for selectivelycontrolling said valve apparatus, and a charge of insulating liquidarranged in said overhead space and in contact with three bodies of saidsecond solution respectively contained in said three compartments, saidcharge of insulating liquid being incompressible and having a specificgravity lower than that of said second solution and being immisicibletherewith and serving to insulate from each other the three bodies ofsaid second solution respectively contained in said three compartmentsand serving to transmit the pressure of the body of said second solutioncontained in said first compartment to the other two bodies of saidsecond solution respectively contained in said second and thirdcompartments, whereby the discharge of anolyte from said anolyte chambereffects the flow of said second solution from said first compartmentthrough said charge of liquid into said second compartment and thenceinto said anolyte chamber and the discharge of catholyte from saidcatholyte chamber effects the flow of said second solution from saidfirst compartment through said charge of liquid into said thirdcompartment and thence into said catholyte chamber.

15. The system set forth in claim 14, wherein said valve apparatus isopened in response to relatively high concentrations of ions in saidanolyte and in said catholyte and is closed in response to relativelylow concentrations of ions in said anolyte and in said catholyte.

1-6. In antele ctrolytic system, a unit including structure defining atreatment chamber and ananolyte cham- 17 ber and a catholyte chamber,said structure including a first porous diaphragm as a common wallbetween'said treatment chamber and said anolyte chamber and a second'porous diaphragm as a common wall between said treatment chamber andsaid catholyte chamber, an anode in said anolyte chamber, a cathode insaid catholyte chamber, means for supplying an aqueous solutioncontaining an electrolyte into said treatment chamber under pressure,said first diaphragm being characterized by the passage of said solutiontherethrough from said treatment chamber into said anolyte chamber whenthe pressure of said solution in said treatment chamber is somewhatgreater than that of the anolyte in said anolyte chamber, said seconddiaphragm being characterized by the passage of said solutiontherethrough from said treatment chamber into said catholyte chamberwhen the pressure of said solution in said treatment chamber is somewhatgreater than that of the catholyte in said catholyte chamber, firstfloat-valve means for controlling the venting of gas from said anolytechamber to the exterior when said anolyte chamber contains less thansubstantially a complete filling of anolyte, second float-valve meansfor controlling the venting of gas from said catholyte chamber to theexterior when said catholyte chamber contains less than substantially acomplete filling of catholyte, means for applying a direct voltagebetween said anode and said cathode, whereby said first aqueous solutionis subjected to electrodialysis with the migration of the anions and thecations therein respectively into the anolyte contained in said anolytechamber and into the catholyte contained in said catholyte chamber, andvalve apparatus for controlling the discharge of anolyte from saidanolyte chamber to the exterior and the discharge of catholyte from saidcatholyte chamber to the exterior, and automatic means governed by theion concentration in said anolyte and in said catholyte for selectivelycontrolling said valve apparatus.

17. The system set forth in claim l6, and further comprising a mass ofcatalyst arranged in the gas vent from said second float-valve means andcharacterized 'by the promotion of a water-producing reaction involvndporous diaphragm as a common wall between said treatment chamber andsaid catholyte chamber, an anode in said anolyte chamber, a cathode insaid catholyte chamber, means for supplying an aqueous solutioncontaining an electrolyte into said treatment chamber under pressure,said first diaphragm being characterized by the passage of said solutiontherethrough from said treat-;

ment chamber into said anolyte chamber when the pressure of saidsolution in said treatment chamber is some what greater than that of theanolyte in said anolyte chamber, said second diaphragm beingcharacterized by the passage of said solution therethrough from saidtreatment chamber into said catholyte chamber when the pressure of saidsolution in said treatment chamber is somewhat greater than that of thecatholyte in said catholyte chamber, first float-valve means forcontrolling the venting of gas from said anolyte chamber to the exteriorwhen said anolyte chamber contains less than substantially a completefilling of anolyte, second float-valve means for controlling the ventingof gas from said catholyte chamber to the exterior when said catholytechamber contains less than substantially a complete filling ofcatholyte, means for applying a direct voltage between said anode andsaid cathode, whereby said first aqueous solution is subjected toelectrodialysis with the migration of the anions and the cations thereinrespectively into the anolyte contained in said anolyte chamber andintothe catholyte contained in said catholytelchambereso that the ionconcentrations therein are increased, valve 'appa-" ratus forcontrolling the discharge ot,.anolyte from;said

anolyte chamber tov the exterior: and the discharger of catholyte fromsaid catholyte chamber -to, the exterior and automatic means governed bythe ion concentrations in said anolyte and in said catholyte-forselectively con-f trolling said valve apparatus. a 19. The system set-forth .in.; cl

valve apparatus is opened in response to relatively high concentrationsof ions in said anolyte and in said catholyte and is closed in responseto relatively low concentrations of ions in said anolyte and in saidcatholyte.

20. In an electrolytic system, a unit including first structure defininga treatment chamber and an anolyte chamber and a catholyte chamber witha first permeable diaphragm as a common wall between said treatmentchamber and said anolyte chamber and with a second permeable diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber, means for supplying an aqueous solution containing anelectrolyte into said treatment chamber under pressure, means forsupplying an anolyte into said anolyte chamber under pressure, means forsupplying a catholyte into said catholyte chamber under pressure,

first float-valve means for controlling the venting of gas,

means for applying a direct voltage between said anode and said cathode,whereby said first aqueous solution is subjected to electrodialysis withthe migration of thc anions and the cations therein respectively intothe ano-, lyte contained in said anolyte chamber and into the catholytecontained in said catholyte chamber, and valve apparatus for controllingthe discharge of anolyte from said anolyte chamber to the exterior andthe discharge of catholyte from said catholyte chamber to the exterior,and automatic means governed by the ion concentrations in said anolyteand in said catholyte for selectively controlling said valve apparatus.

21. In an electrolytic system, a unit including first structure defininga treatment chamber and an anolyte chamber and a catholyte chamber witha first permeable diaphragm as a common wall between said treatmentchamber and said anolyte chamber and with a second permeable diaphragmas a common wall between said treatment chamber and said catholytechamber, an anode in said anolyte chamber, a cathode in said catholytechamber, means for supplying an aqueous solution containing anelectrolyte into said treatment chamber under pressure, means forsupplying an anolyte into said anosaid cathode, whereby said firstaqueous solution is subjected to electrodialysis with the migration ofthe anions and the cations therein respectively into the anolytecontained in said anolyte chamber and into the catholyte contained insaid catholyte chamber, so that the ionconcentrations therein areincreased, valve apparatus for controlling the discharge of anolyte fromsaid anolyte chamber to the exterior and the discharge of catholyte fromsaid catholyte chamber to the exterior, and automafde means gqvemed byth ionconcemrations in said andly te and-i1 1: said eathnlyte. vforselectively. 'conirdlling said-valv'eihpparatusb* r 22; Thes ystin 's'tfdi'thdd claim 21, wherein said valve apfiffit us'fisjbpelied ihres'lionse to relatively" high coneehu gt idns bf ions insaid anolyteand in saidcatholyte and is closed in responsetorelatively lowconcentrationsflifdiw -in s'ai'd" anolyte and'in said catho1yte.

References Cited, in fil e of this patent UNITED STATES PATENTS wAderer' July 27, 1915 Simsohn. A1 1g,,23,' 1 921" Gqrdo nz, May 17,1949,

Sqthard; Aug. 19,1932 f Suthard Feb. 19,1957 Pearson Nov. 5, 1957Stoddard Mar. 4, 1958 V r/ I ;i.i imware 7 UNITED STATES PATENT OFFICECERTHHCATE OF CORRECTHNN Patent No. 2 946 733 Joseph Jq Gaysowski July26 1960 It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 14 line 52, before "fresh" insert flow of =9 (SEAL) Attest:ERNEST W. SWIDER XXBXXXW Attes ting Oflicer I o ARTHUR w. CROCKER ActlngCommissioner of Patents

1. IN A WATER DEMINERALINZING SYSTEM: A DEMINERALIZING UNIT INCLUDINGSTRUCTURE DEFINING A TREATMENT CHAMBER AND AN ANOLYTE CHAMBER AND ACATHOLYTE CHAMBER WITH A FIRST DIAPHRAGM AS A COMMON WALL BETWEEN SAIDTREATMENT CHAMBER AND SAID ANOLYTE CHAMBER AND WITH A SECOND DIAPHRAGMAS A COMMON WALL BETWEEN SAID TREATMENT CHAMBER AND SAID CATHOLYTECHAMBER, AN ANODE IN SAID ANOLYTE CHAMBER, A CATHODE IN SAID CATHCLYTECHAMBER, AND A POROUS ION EXCHANGE BED ARRANGED IN SAID TREATMENTCHAMBER AND CHARACTERIZED BY BOTH CATION EXCHANGE AND ANION EXCHANGE, ANINLET PIPE ADAPTED TO CONTAIN RAW WATER UNDER PRESSURE AND CONNECTED TOSAID TREATMENT CHAMBER, AN OUTLET PIPE ADAPTED TO CONTAIN DEMINERALIZEDWATER UNDER PRESSURE AND CONNECTED TO SAID TREATMENT CHAMBER, VALVEMECHANISM FOR CONTROLLING THE FLOW OF WATER FROM SAID INLET PIPE THROUGHSAID TREAMENT CHAMBER AND INTO CONTACT WITH SAID ION EXCHANGE BED ANDTHENCE THOUGH SAID OULET PIPE WITH THE RESULT THAT THE RAW WATER PASSINGTHROUGH SAID TREATMENT CHAMBER IS DEMINERALIZED AND SAID ION EXCHANGEBED IS CORRESPONDINGLY DEGENERATED, FIRST CONDUIT MEANS FOR SUPPLYINGFRESH ANOLYTE INTO SAID ANOLYTE CHAMBER, SECOND CONDUIT MEANS FORSUPPLYING FRESH CATHOLYTE INTO SAID CATHOLYTE CHAMBER, A POWER CIRCUITFOR CONDUCTING A DIRECT CURRENT FROM SAID ANODE TO SAID CATHODE, WHEREBYSAID ION EXCHANGE BED IS REGENERATED WITH THE MIGRATION OF THE SORBEDANIONS AND CATIONS OF THE MINERAL SALTS RESPECTIVELY INTO SAID ANOLYTEAND INTO SAID CATHOLYTE WITH THE RESULT THAT ION CONCENTRATIONS THEREINARE INCREASED, VALVE APPARATUS FOR CONTROLLING THE SUPPLY OF FRESHANOLYTE FROM SAID FIRST CONDUIT MEANS INTO SAID ANOLYTE CHAMBER AND THESUPPLY OF FRESH CATHOLYTE FROM SAID SECOND CONDUIT MEANS INTO SAIDCATHOLYTE CHAMBER, AND AUTOMATIC MEANS GOVERNED BY THE IONCONCENTRATIONS IN SAID ANOLYTE AND IN SAID CATHOLYTE FOR SELECTIVELYCONTROLLING SAID VALVE APPARATUS, SO THAT SAID VALVE APPARATUS IS OPENIN RESPONSE TO RELATIVELY HIGH CONCENTRATIONS OF IONS IN SAID ANOLYTEAND IN SAID CATHOLYTE AND IS CLOSED IN REPONSE TO RELATIVELY LOWCONCENTRATIONS OF IONS IN SAID ANOLYTE AND IN SAID CATHOLYTE.